From f70ad448741580bf61cdfbeb02229c581409760a Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 28 Jun 2021 17:26:00 -0400 Subject: [PATCH] mm/memcg: Add folio_memcg_lock() and folio_memcg_unlock() These are the folio equivalents of lock_page_memcg() and unlock_page_memcg(). lock_page_memcg() and unlock_page_memcg() have too many callers to be easily replaced in a single patch, so reimplement them as wrappers for now to be cleaned up later when enough callers have been converted to use folios. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: Mike Rapoport Reviewed-by: David Howells Acked-by: Vlastimil Babka --- include/linux/memcontrol.h | 10 +++++++++ mm/memcontrol.c | 45 ++++++++++++++++++++++++-------------- 2 files changed, 39 insertions(+), 16 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 1c2776c3a223..be85450f066f 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -978,6 +978,8 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg); extern bool cgroup_memory_noswap; #endif +void folio_memcg_lock(struct folio *folio); +void folio_memcg_unlock(struct folio *folio); void lock_page_memcg(struct page *page); void unlock_page_memcg(struct page *page); @@ -1397,6 +1399,14 @@ static inline void unlock_page_memcg(struct page *page) { } +static inline void folio_memcg_lock(struct folio *folio) +{ +} + +static inline void folio_memcg_unlock(struct folio *folio) +{ +} + static inline void mem_cgroup_handle_over_high(void) { } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 4a04bddefdbc..23fe124fe78d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1933,18 +1933,17 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) } /** - * lock_page_memcg - lock a page and memcg binding - * @page: the page + * folio_memcg_lock - Bind a folio to its memcg. + * @folio: The folio. * - * This function protects unlocked LRU pages from being moved to + * This function prevents unlocked LRU folios from being moved to * another cgroup. * - * It ensures lifetime of the locked memcg. Caller is responsible - * for the lifetime of the page. + * It ensures lifetime of the bound memcg. The caller is responsible + * for the lifetime of the folio. */ -void lock_page_memcg(struct page *page) +void folio_memcg_lock(struct folio *folio) { - struct page *head = compound_head(page); /* rmap on tail pages */ struct mem_cgroup *memcg; unsigned long flags; @@ -1958,7 +1957,7 @@ void lock_page_memcg(struct page *page) if (mem_cgroup_disabled()) return; again: - memcg = page_memcg(head); + memcg = folio_memcg(folio); if (unlikely(!memcg)) return; @@ -1972,7 +1971,7 @@ again: return; spin_lock_irqsave(&memcg->move_lock, flags); - if (memcg != page_memcg(head)) { + if (memcg != folio_memcg(folio)) { spin_unlock_irqrestore(&memcg->move_lock, flags); goto again; } @@ -1986,9 +1985,15 @@ again: memcg->move_lock_task = current; memcg->move_lock_flags = flags; } +EXPORT_SYMBOL(folio_memcg_lock); + +void lock_page_memcg(struct page *page) +{ + folio_memcg_lock(page_folio(page)); +} EXPORT_SYMBOL(lock_page_memcg); -static void __unlock_page_memcg(struct mem_cgroup *memcg) +static void __folio_memcg_unlock(struct mem_cgroup *memcg) { if (memcg && memcg->move_lock_task == current) { unsigned long flags = memcg->move_lock_flags; @@ -2003,14 +2008,22 @@ static void __unlock_page_memcg(struct mem_cgroup *memcg) } /** - * unlock_page_memcg - unlock a page and memcg binding - * @page: the page + * folio_memcg_unlock - Release the binding between a folio and its memcg. + * @folio: The folio. + * + * This releases the binding created by folio_memcg_lock(). This does + * not change the accounting of this folio to its memcg, but it does + * permit others to change it. */ -void unlock_page_memcg(struct page *page) +void folio_memcg_unlock(struct folio *folio) { - struct page *head = compound_head(page); + __folio_memcg_unlock(folio_memcg(folio)); +} +EXPORT_SYMBOL(folio_memcg_unlock); - __unlock_page_memcg(page_memcg(head)); +void unlock_page_memcg(struct page *page) +{ + folio_memcg_unlock(page_folio(page)); } EXPORT_SYMBOL(unlock_page_memcg); @@ -5643,7 +5656,7 @@ static int mem_cgroup_move_account(struct page *page, page->memcg_data = (unsigned long)to; - __unlock_page_memcg(from); + __folio_memcg_unlock(from); ret = 0; nid = page_to_nid(page); -- 2.25.1